More specifically, the invention relates to a spray device comprising:                a piezoelectric element,        a sonotrode comprising a base coupled to the piezoelectric element and a horn tube narrower than the base extending along a longitudinal axis from the base to a horn mouth that is wider than the horn tube, said horn mouth having a front face directed away from the horn tube,        a control circuit designed to cause the piezoelectric element to vibrate,        and a feed device for feeding product that is to be sprayed, this feed device being designed to carry the product that is to be sprayed as far as the front face of the horn mouth,the sonotrode vibrating in a mode parallel to the longitudinal axis, the horn mouth being sized to move essentially along said longitudinal axis without flexing when the control circuit causes the piezoelectric element to vibrate.        
Document EP-A-0 389 665 describes an example of a spray device such as this.